Anodization architecture for electro-plate adhesion

ABSTRACT

A chamber component for a processing chamber comprises a metallic article that comprises impurities. The chamber component further comprises a first anodization layer on the metallic article, the first anodization layer having a thickness greater than about 100 nm. The first anodization layer comprises a dense barrier layer portion and a porous columnar layer portion over the dense barrier layer portion, wherein the porous columnar layer portion comprises a plurality of pores that are free from moisture. The chamber component further comprises an aluminum coating on the first anodization layer, the aluminum coating being substantially free from impurities.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/463,001 filed on Aug. 19, 2014, which claims the benefit ofU.S. Provisional Application Ser. No. 61/871,807 filed on Aug. 29, 2013,both of which are hereby incorporated by reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate, in general, to aluminumcoated articles and to a process for applying an aluminum coating to asubstrate.

BACKGROUND

In the semiconductor industry, devices are fabricated by a number ofmanufacturing processes producing structures of an ever-decreasing size.Some manufacturing processes such as dry etch may generate particles andmetal contamination on the substrate that is being processed,contributing to device defects. As device geometries shrink,susceptibility to these defects increases, and particle and metalcontamination requirements become more stringent. Accordingly, as devicegeometries shrink, allowable levels of particle defects and metalcontamination may be reduced significantly.

SUMMARY

In one embodiment, a first anodization layer with a thickness greaterthan about 100 nm is formed on a metallic article that includesimpurities and inclusions, and an aluminum coating substantially freefrom impurities and inclusions is formed on the first anodization layer,the aluminum coating being substantially free from impurities.

The aluminum coating can have a thickness in a range from about 20microns to about 80 microns. The anodized metallic article may not be DIsealed post anodization. The anodized metallic article can be heated toa temperature in a range from about 60 degrees C. to about 150 degreesC. for a time in a range from about 2 hours to about 12 hours prior tothe aluminum coating being formed on the anodization layer. A secondanodization layer can be formed on the aluminum coating and can have athickness in a range from about 5 microns to about 30 microns. Anaverage surface roughness (Ra) of the metallic article prior toanodization can be in a range from about 15 micro-inch to about 300micro-inch.

A composite ceramic layer can be formed on the aluminum coating and canhave a thickness in a range from about 50 microns to about 300 microns.The article can be Al 6061. The aluminum coating can be electroplated onthe article.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 illustrates a chamber component for use in a semiconductormanufacturing chamber, in accordance with one embodiment of the presentinvention.

FIG. 2 illustrates an exemplary architecture of a manufacturing system,in accordance with one embodiment of the present invention.

FIG. 3 illustrates cross-sectional side views of an article duringdifferent stages of a manufacturing process, in accordance withembodiments of the present invention.

FIG. 4 illustrates a process for anodizing an article, in accordancewith one embodiment of the present invention.

FIG. 5 illustrates a process for forming an aluminum coating on anarticle, in accordance with one embodiment of the present invention.

FIG. 6 is a flow chart showing a process for manufacturing an article,in accordance with embodiments of the present invention.

FIGS. 7A, 7B, and 7C illustrate additional cross-sectional micrographviews of layers on an article, in accordance with embodiments of thepresent invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the disclosure are directed to a process for anodizing anarticle (e.g., an article for use in semiconductor manufacturing) toform an anodization layer of a certain thickness (e.g., greater thanabout 100 nm) and coating the article with an aluminum coating, and toan article created using such a coating process. For example, thearticle may be a showerhead, a cathode sleeve, a sleeve liner door, acathode base, a chamber liner, an electrostatic chuck base, etc. of achamber for processing equipment such as an etcher, a cleaner, afurnace, and so forth. In one embodiment, the chamber is for a plasmaetcher or plasma cleaner. In one embodiment, these articles can beformed of an aluminum alloy (e.g., Al 6061), another alloy, a metal, ametal oxide, or any other suitable material (e.g., a conductivematerial). In one embodiment, a composite ceramic layer can be formedover the aluminum coating.

Due to impurities in the metals used to manufacture semiconductorchamber components (e.g., Al 6061), these components may not meet somesemiconductor manufacturing specifications. For example, metalcontamination specifications for device nodes having sizes of less than90 nm may be stringent. These impurities can leach out of typical coatedor anodized articles during plasma processing of a wafer and increasecontamination levels. However, pure aluminum may not be a suitablematerial for manufacture of these components due to lower structuralstrength. Also, substantially pure aluminum coated on typicalanodization microstructures may have low adhesion (e.g., less than about10 MPa) due to a low aspect ratio of anodization column height to gapdiameter (also referred to as pore diameter) between anodizationcolumns. This may lead to a low shear resistance of the aluminumcoating. Further, anodization can result in sufficient moistureretention between anodization columns to create a sealing layer. Such asealing layer reduces infiltration of the successive pure aluminum intothe gaps or pores between the anodization columns, leading to furtherreduced adhesion of the aluminum coating. According to embodiments,parameters for anodization of these components (e.g., a thickness of ananodization layer) may be optimized to reduce metal contamination fromthe article and increase adhesion of an aluminum coating. One suchexample parameter for anodization is a thickness of an anodizationlayer. Performance properties of the article may include a relativelylong lifespan, and a low on-wafer metal contamination, according toembodiments.

Embodiments described herein may cause reduced on wafer metalcontamination when used in a process chamber for plasma rich processes.However, it should be understood that the aluminum coated articlesdiscussed herein may also provide reduced metal contamination when usedin process chambers for other processes such as non-plasma etchers,non-plasma cleaners, chemical vapor deposition (CVD) chamber, physicalvapor deposition (PVD) chamber, and so forth.

When the terms “about” and “approximately” are used herein, these areintended to mean that the nominal value presented is precise within±10%. The articles described herein may be other structures that areexposed to plasma.

FIG. 1 illustrates a cross-sectional view of a chamber component 100 foruse in a semiconductor manufacturing chamber, in accordance with oneembodiment of the present invention. The chamber component 100 includesan article 102, an anodization layer 104, an aluminum coating 106, and asecond anodization layer 108. The chamber component 100 shown is forrepresentational purposes and is not necessarily to scale.

The article 102 can be a semiconductor chamber component, which aretypically manufactured of aluminum alloys (e.g., 6061 Al). However, thearticle 102 can also be formed of any other suitable material, such asother metals or metal alloys. According to embodiments, the article canbe a showerhead, a cathode sleeve, a sleeve liner door, a cathode base,a chamber liner, an electrostatic chuck base, etc. of a chamber forprocessing equipment such as an etcher, a cleaner, a furnace, and soforth.

In one embodiment, the surface roughness of the article 102 is in arange from about 15 micro-inches to about 300 micro-inches (e.g., about120 micro-inches). The article 102 may have been initially formed suchthat the surface roughness is in the above range. However, the surfaceroughness of the article 102 can be adjusted by either reducing thesurface roughness (e.g., by polishing or sanding) or increasing thesurface roughness (e.g., by bead blasting or grinding). The surfaceroughness can be optimized for different applications, such as differentlocations of the article within the semiconductor manufacturing chamber.

The article 102 is anodized (e.g., via oxalic anodization) to form theanodization layer 104 on a surface of the article 102, where pores 112are formed between anodization columns 110 formed of Al₂O₃. Theanodization layer 104 can be formed to have a certain thickness thatresults in an aspect ratio of the anodization column 110 height to thepore diameter being in a range from about 10 to 1 (10:1) to about 2000to 1 (2000:1). Such aspect ratios may ensure pores 112 that are suitablydeep in some embodiments. For example, pore diameter is typically in arange from about 10 nm to about 50 nm (e.g., about 30 nm), so an aspectratio of 10 to 1 would result in the anodization layer 104 having athickness of about 300 nm. In another example, an aspect ratio of 2000to 1 would result in the anodization layer 104 having a thickness ofabout 60 microns. The formation of the anodization layer 104 will bediscussed below in greater detail.

The aluminum coating 106 can then be formed (e.g., via electroplating orany other suitable method) over the anodization layer 104. In oneembodiment, deionized water (DI) sealing is not performed prior toforming the aluminum coating 106 so that moisture is not added to thepores 112. Further, the article 102 with the anodization layer 104 canbe baked to further remove moisture from the pores 112, according to oneembodiment. Such baking may be for a time in a range from about 2 toabout 12 hours at a temperature in a range from about 60 degrees C. toabout 150 degrees C.). For example, the article 102 with the anodizationlayer 104 can be baked for about 6 hours at about 95 degrees C. Theformation of the aluminum coating 106 will be discussed below in greaterdetail.

As the aluminum coating 106 is formed on the anodization layer 104,portions 114 of the aluminum coating 106 can infiltrate the pores 112.Because the pores 112 are suitably deep and are not otherwise blocked bymoisture, the portions 114 of the aluminum coating 106 that infiltrateinto the pores 112 are long enough to suitably adhere the aluminumcoating 106 to the anodization layer 104. As a result, the adhesion ofthe aluminum coating 106 to the article is improved over typicalaluminum coatings. In one embodiment, the thickness of the aluminumcoating can be in a range from about 20 microns to about 80 microns(e.g., about 50 microns).

In one embodiment, the aluminum coating 106 can be anodized to form asecond anodization layer 108 formed of Al₂O₃ from the aluminum coating106, in a manner similar to the anodization described above. The secondanodization layer 108 can protect the aluminum coating 106 from wear andtear during use of the chamber component 100. Further, as a result ofhaving a pure aluminum coating (e.g., an ultra-pure Al coating), thesecond anodization layer 108 is relatively pure. Therefore, exposure toplasma chemistry will result in less metal contamination. Also, thesecond anodization layer 108 is more plasma-resistant than barealuminum. In one embodiment, the thickness of the second anodizationlayer 108 can be in a range from about 5 microns to about 30 microns.However, this second anodization layer 108 can be optional. The range ofadhesion strength can be between from about 5 to about 100 MPa.

In one embodiment, a ceramic layer can be formed over the aluminumcoating 106 or the second anodization layer 108. The ceramic layer canbe a ceramic composite layer formed of any suitable material such as aY₂O₃, Al₂O₃ , ZrO₂ or a mixture of these metal oxides. The ceramic layercan have a thickness in a range from about 100 microns to about 300microns (e.g., in a range from about 200 microns to about 250 microns).Alternatively, the ceramic layer may have a thickness of about 2-10microns in one embodiment. The ceramic composite layer can help toprotect the chamber component 100, and can improve particle performanceof the component.

FIG. 2 illustrates an exemplary architecture of a manufacturing system200 for manufacturing a chamber component (e.g., chamber component 100of FIG. 1). The manufacturing system 200 may be a system formanufacturing an article for use in semiconductor manufacturing. In oneembodiment, the manufacturing system 200 includes processing equipment201 connected to an equipment automation layer 215. The processingequipment 201 may include a bead blaster 203, an aluminum coater 204and/or an anodizer 205. The manufacturing system 200 may further includeone or more computing devices 220 connected to the equipment automationlayer 215. In alternative embodiments, the manufacturing system 200 mayinclude more or fewer components. For example, the manufacturing system200 may include manually operated (e.g., off-line) processing equipment201 without the equipment automation layer 215 or the computing device220.

The bead blaster 203 can adjust a surface roughness of an article priorto any layers or coatings being formed. For example, the bead blaster203 may adjust a surface roughness of the article to be in a range fromabout 15 micro-inches to about 300 micro-inches (e.g., about 120micro-inches). In other embodiments, the surface roughness of thearticle may be increased by grinding, or may be decreased by sanding orpolishing. However, the surface roughness of the article may already besuitable, so surface roughness adjustment can be optional. Surfaceroughness adjustment will be described in greater detail below.

In one embodiment, a wet cleaner cleans the article using a wet cleanprocess where the article is immersed in a wet bath (e.g., after surfaceroughness adjustment or prior to coatings or layers being formed). Inother embodiments, alternative types of cleaners such as dry cleanersmay be used to clean the articles. Dry cleaners may clean articles byapplying heat, by applying gas, by applying plasma, and so forth. In oneembodiment, the article is not cleaned in a wet cleaner (not shown)after anodization to form an anodization layer. Furthermore, afteranodization, the article can be baked in a heating apparatus (e.g., anoven) for certain period (e.g., 2 hours to 12 hours) at a certaintemperature (e.g., 60 degrees C. to 150 degrees C.) to remove residualmoisture from the article and/or the anodization layer.

In one embodiment, anodizer 205 is a system configured to form ananodization layer on the aluminum coating. For example, the article(e.g., a conductive article) is immersed in an anodization bath, e.g.,including sulfuric acid, oxalic acid, phosphoric acid, or a mixture ofthese acids and an electrical current is applied to the article suchthat the article is an anode. The anodization layer then forms on thealuminum coating on the article, which will be described in more detailbelow.

In one embodiment, the article is not cleaned in a wet cleaner afteranodization to form an anodization layer. Furthermore, afteranodization, the article can be baked in a heating apparatus (e.g., anoven) for certain period (e.g., 2 hours to 12 hours) at a certaintemperature (e.g., 60 degrees C. to 150 degrees C.) to remove residualmoisture from the article and/or the anodization layer.

Aluminum coater 204 is a system configured to apply an aluminum coatingto the surface of the article. In one embodiment, aluminum coater 204 isan electroplating system that plates the aluminum on the article (e.g.,a conductive article) by applying an electrical current to the articlewhen the article is immersed in an electroplating bath includingaluminum, which will be described in more detail below. Here, surfacesof the article can be coated evenly because the conductive article isimmersed in the bath. In alternative embodiments, the aluminum coater204 may use other techniques to apply the aluminum coating such asphysical vapor deposition (PVD), chemical vapor deposition (CVD), twinwire arc spray, ion vapor deposition, sputtering, and cold spray. Theformation of the aluminum coating will be described in more detailbelow.

The equipment automation layer 215 may interconnect some or all of themanufacturing machines 201 with computing devices 220, with othermanufacturing machines, with metrology tools and/or other devices. Theequipment automation layer 215 may include a network (e.g., a locationarea network (LAN)), routers, gateways, servers, data stores, and so on.Manufacturing machines 201 may connect to the equipment automation layer215 via a SEMI Equipment Communications Standard/Generic Equipment Model(SECS/GEM) interface, via an Ethernet interface, and/or via otherinterfaces. In one embodiment, the equipment automation layer 215enables process data (e.g., data collected by manufacturing machines 201during a process run) to be stored in a data store (not shown). In analternative embodiment, the computing device 220 connects directly toone or more of the manufacturing machines 201.

In one embodiment, some or all manufacturing machines 201 include aprogrammable controller that can load, store and execute processrecipes. The programmable controller may control temperature settings,gas and/or vacuum settings, time settings, etc. of manufacturingmachines 201. The programmable controller may include a main memory(e.g., read-only memory (ROM), flash memory, dynamic random accessmemory (DRAM), static random access memory (SRAM), etc.), and/or asecondary memory (e.g., a data storage device such as a disk drive). Themain memory and/or secondary memory may store instructions forperforming heat treatment processes described herein.

The programmable controller may also include a processing device coupledto the main memory and/or secondary memory (e.g., via a bus) to executethe instructions. The processing device may be a general-purposeprocessing device such as a microprocessor, central processing unit, orthe like. The processing device may also be a special-purpose processingdevice such as an application specific integrated circuit (ASIC), afield programmable gate array (FPGA), a digital signal processor (DSP),network processor, or the like. In one embodiment, programmablecontroller is a programmable logic controller (PLC).

FIG. 3 shows cross sectional side views 310 and 320 of an article duringdifferent stages of a manufacturing process, in accordance withembodiments of the present invention. In one embodiment, the crosssectional side views correspond to a state of chamber component 100 ofFIG. 1 during preparation for anodization by adjusting a surfaceroughness.

Side view 310 shows a hard mask 353 disposed over a protected portion ofa provided article. The provided article may have a metal body (e.g.,formed of AL 6061). The hard mask 353 may prevent the protected portionfrom becoming roughened during bead blasting. The article is roughenedby a bead blaster (or other ceramic roughener). In one embodiment, thebead blaster uses ceramic beads to blast a surface of the article. Inone embodiment, the ceramic beads have a size range of approximately0.2-2 mm. The bead blaster may bead blast the article with an airpressure of approximately 30-90 psi and a working distance ofapproximately 50-150 mm, and the blasting angle to the body should beabout or slightly less than 90 degree. The bead blaster may roughenexposed portions of the body of the article (those portions not coveredby the mask).

Side view 320 shows the article 352 after bead blasting has beenperformed. The article 352 has a roughened surface 358, corresponding toa portion of the article that was not protected during the beadblasting. The article 352 additionally has a smooth surface 357corresponding to a portion of the article that has not been roughened.As shown, a soft mask 356 is disposed on the article 352 over the smoothsurface 357 after the article 352 has been roughened. The soft mask 356may be used to cover a same region of the article 352 that waspreviously protected by the hard mask 353. Side view 320 shows a stateof the article after completion of block 212.

In one embodiment, a processed article has a post-blast roughness in arange from about 15 micro-inch to about 300 micro-inch. The post-blastroughness may be about 120 micro-inch in one embodiment. Roughening thearticle to an optimal roughness may improve adhesion strength ofsubsequent layers or coatings. However, in one embodiment, the articleis not roughened.

FIG. 4 illustrates a process 400 for anodizing an article 403 to form ananodization layer 409, according to one embodiment. For example, article403 can be article 102 of FIG. 1. Anodization changes the microscopictexture of the surface of the article 403, thus FIG. 4 is forillustration purposes only and may not be to scale. Preceding theanodization process, the article 403 can be cleaned in a nitric acidbath, an alkaline solution, or NaOH, or subjected to a chemicaltreatment (e.g., deoxidation) prior to anodization.

The article 403 is immersed in an anodization bath 401, including anacid solution, along with a cathode body 405. Examples of cathode bodiesthat may be used include aluminum alloys such as Al6061 and Al3003 andcarbon bodies. The anodization layer 409 is grown on the article 403 bypassing a current through an electrolytic or acid solution via a currentsupplier 407 (e.g., a battery or other power supply). Here, the article403 is the anode (the positive electrode). The current then releaseshydrogen at the cathode body 405, e.g., the negative electrode, andoxygen at the surface of the article 403 to form an anodization layer409 of aluminum oxide. In embodiments, the voltage that enablesanodization using various solutions may range from 1 to 300 V, or from15 to 21 V. The anodizing current varies with the area of the cathodebody 405 anodized, and can range from 30 to 300 amperes/meter² (2.8 to28 ampere/ft²).

The acid solution dissolves (i.e., consumes or converts) a surface ofthe article 403 (e.g., the aluminum coating) to form a coating of pores(e.g., columnar nano-pores). The anodization layer 409 then continuesgrowing from this coating of nano-pores. The pores may have a diameterin a range from about 10 nm to about 50 nm (e.g., about 30 nm). The acidsolution can be oxalic acid, phosphoric acid, sulfuric acid (Type IIIanodization), or a combination of these acids, or. For oxalic acid, theratio of consumption of the article to anodization layer growth is about1:1. Electrolyte concentration, acidity, solution temperature, andcurrent are controlled to form a consistent aluminum oxide anodizationlayer 409 on the article 403. In one embodiment, the anodization layer409 can be grown to have a thickness in a range from about 100 nm toabout 60 microns.

In one embodiment, the current density is initially high to grow a verydense barrier layer portion of the anodization layer, and then currentdensity is reduced to grow a porous columnar layer portion of theanodization layer. In one embodiment where oxalic acid is used to formthe anodization layer, the porosity is in a range from about 40% toabout 50%, and the pores have a diameter in a range from about 10 nm toabout 50 nm.

In one embodiment, the average surface roughness (Ra) of the anodizationlayer is in a range from about 15 micro-inch to about 300 micro-inch,which can be similar to the initial roughness of the article. In oneembodiment, the average surface roughness is about 120 micro-inches.

FIG. 5 illustrates a process 500 for electroplating an article 503 withan anodization layer 509 with an aluminum coating 511. In oneembodiment, the article 503 is article 102 with anodization layer 104from FIG. 1. Electroplating may produce an aluminum layer having apurity of 99.99. Electroplating is a process that uses electricalcurrent to reduce dissolved metal cations to form a metal coating on anelectrode, e.g., aluminum coating 511 on article 503 with anodizationlayer 509. The article 503 is the cathode, and an aluminum body 505(e.g., high purity aluminum) is the anode. Both components are immersedin an aluminum plating bath 501 including an electrolyte solutioncontaining one or more dissolved metal salts as well as other ions thatpermit the flow of electricity. A current supplier 507 (e.g., a batteryor other power supply) supplies a direct current to the article 503. Thedirect current oxidizes the metal atoms of the aluminum body 505 suchthat the metal atoms dissolve in the solution. The dissolved metal ionsin the electrolyte solution are reduced at the interface between thesolution and the article 503 to plate onto the article 503 and form analuminum coating 511 or aluminum plating layer. According to anembodiment, the metal ions also infiltrate the pores of the anodizationlayer 509 to form portions of the aluminum coating 511 that extend intothe anodization layer 509. These portions of the aluminum coating 511that extend into the anodization layer 509 help to improve adhesion ofthe aluminum coating 511 to the article 503 by better anchoring thealuminum coating through the high aspect ratio columnar structure of thebase anodization.

In one embodiment, the aluminum coating 511 is smooth. For example, thealuminum plating may have an average surface roughness (Ra) of about 20micro-inch to about 300 micro-inch.

In one embodiment, the aluminum coating 511 thickness is optimized forboth cost savings and adequate thickness for contamination prevention.The thickness of the aluminum coating can be chosen such an anodizationlayer with a thickness in a range from about 25 to about 75 μm can beformed from the aluminum coating without anodizing the entire aluminumcoating. In one embodiment, the aluminum coating 511 has a thickness ofin a range from about 20 microns to about 80 microns (e.g., about 50microns in one embodiment). Note that other aluminum coating processesother than electroplating may also be used in other embodiments, such ashigh-velocity oxy-fuel spray (HVOF).

FIG. 6 is a flow chart showing a method 600 for manufacturing analuminum coated article, in accordance with embodiments of the presentdisclosure. The operations of method 600 may be performed by variousmanufacturing machines, as set forth in FIG. 2.

At block 601, an article (e.g., an article having at least a conductiveportion) is provided. For example, the article can be a conductivearticle formed of an aluminum alloy (e.g., Al 6061). The article can bea shower head, a cathode sleeve, a sleeve liner door, a cathode base, achamber liner, an electrostatic chuck base, etc., for use in aprocessing chamber.

At block 603, the article is prepared for coating, according to oneembodiment. The surface of the article may be altered by roughening,smoothing, or cleaning the surface.

At block 605, the article is anodized to form an anodization layer(e.g., formed of Al₂O₃), according to one embodiment. For example, thearticle can be anodized in a bath of oxalic acid or sulfuric acid, assimilarly described with respect to FIG. 4, to form an anodization layerhaving a thickness in a range from about 300 nm to about 60 microns. Inone embodiment, the article can be baked after anodization, as describedabove, to remove residual moisture from pores of the anodization layer.

At block 607, the article is coated (e.g., plated) with an aluminumcoating (e.g., a substantially pure aluminum coating). For example, thearticle can be electroplated with aluminum, as similarly described withrespect to FIG. 5, to form an aluminum coating having a thickness in arange from about 20 microns to about 80 microns. In other examples, thecoating can be applied by physical vapor deposition (PVD), chemicalvapor deposition (CVD), twin wire arc spray, ion vapor deposition,sputtering, and cold spray.

At block 609, the article is anodized to form a second anodization layeron the aluminum coating, according to one embodiment. The secondanodization layer (e.g., formed of Al₂O₃ as described above) can have athickness in a range from about 5 microns to about 30 microns. However,this second anodization layer can be optional.

At block 611, the article is coated with a plasma resistant ceramiclayer, according to one embodiment. A side of the article that will beexposed to a plasma environment may be coated. In one embodiment, aplasma sprayer is used to plasma spray the ceramic coating onto thearticle. In one embodiment, portions of the article that are not to becoated are masked prior to coating. However, this ceramic layer can beoptional.

In one embodiment, mixed raw ceramic powders are sprayed onto thearticle. The article may be heated to a temperature of approximately50-70° C. during the plasma spraying. In one embodiment, a plasma powerof approximately 35-36.5 Watts (W) is used to plasma spray the article,though other plasma powers may also be used. The plasma spray processmay be performed in multiple spray passes. In one embodiment,approximately 35-40 spray passes are applied to create a ceramiccoating. In one example, the coating can have a thickness ofapproximately 5-50 mil.

In one embodiment, the ceramic coating is a yttrium oxide containingceramic or other yttrium containing oxide that is deposited on theceramic body using a thermal spraying technique (e.g., a plasma sprayingtechnique). Thermal spraying techniques (e.g., plasma sprayingtechniques) may melt materials (e.g., ceramic powders) and spray themelted materials onto the article. The thermally sprayed or plasmasprayed composite ceramic layer may have a thickness in a range fromabout 100 microns to about 300 microns (e.g., a thickness in a rangefrom about 200 microns to about 250 microns).

In one embodiment, the ceramic coating is produced from raw ceramicpowders of Y₂O₃, Al₂O₃ and ZrO₂ that are mixed together. These rawceramic powders may have a purity of 99.9% or greater in one embodiment.The raw ceramic powders may be mixed using, for example, ball milling.The raw ceramic powders may have a powder size of approximately 0.5-5μm. In one embodiment, the raw ceramic powders have a powder size ofapproximately 1 μm. After the ceramic powders are mixed, they may becalcinated at a calcination temperature of approximately 1200-1600° C.(e.g., 1400° C. in one embodiment) and a calcination time ofapproximately 5-10 days (e.g., 3 days in one embodiment). The spraydried granular particle size for the mixed powder may have a sizedistribution of approximately 3-50 μm. In one embodiment, the mediansize is about 15 μm. In another embodiment, the median size is about 25μm.

Additionally, the ceramic coating may have an adhesion strength ofapproximately 4-25 MPa (e.g., greater than approximately 14 MPa in oneembodiment). Adhesion strength may be determined by applying a normalforce (e.g., measured in megapascals) to the ceramic coating until theceramic coating peels off from the article.

The article may then be tested for particles. Measured parameters thatrepresent particle count are a tape peel test particle count and aliquid particle count (LPC). A tape test may be performed by attachingan adhesive tape to the ceramic coating, peeling the tape off, andcounting a number of particles that adhere to the tape. The LPC may bedetermined by placing the article in a water bath (e.g., a de-ionized(DI) water bath) and sonicating the water bath. A number of particlesthat come off in the solution may then be counted using, for example, alaser counter. FIGS. 7A, 7B, and 7C illustrate scanning electronmicrographs 702, 704, and 706, respectively, of cross-sectional views ofAl6061 articles with an anodization layer formed in an oxalic acid bathwith a 200 nm scale. The pores have a diameter of about 30 nm.

Table 1 shows an example of electroplated aluminum coating adhesion testresults according to an embodiment, where adhesion strength of sampleswith various anodization layer types and thicknesses was measured. Testcoupons were fabricated with a base anodization layer type of eitheroxalic or type III, where the base anodization layer thickness wasvaried between 0.3 μm, 3 μm and 10 μm for each anodization layer type.To improve electroplated layer adhesion, there was no deionized watersealing of the test coupons post anodization. The coupons weresubsequently electroplated with a high purity Aluminum layer with athickness of about 50 microns. The coupons were then anodized to formeither an oxalic or type III anodization layer with thicknesses thatvaried between 10 μm and 30 μm for each anodization type. An adhesiontest was then performed per ASTM633C, where the test coupons were gluedto an unprocessed coupon using high strength adhesive, and then the testcoupon and the unprocessed coupon were pulled apart. The failure forceneeded to pull the coupons apart was measured as the adhesion strength,where, in an example, an adhesion strength of 30 MPa can be a thresholdstrength for desired performance.

TABLE 1 Coating Adhesion Test Results Type III Type III Oxalic secondOxalic second second second anodization anodization anodizationanodization layer with 10 layer with 30 layer with 10 layer with 30micron micron micron micron Table 1 thickness thickness thicknessthickness Oxalic first anodization 36 MPa 35 MPa 37 MPa 35 MPa layerwith 0.3 micron thickness Oxalic first anodization 37 MPa 38 MPa 33 MPa32 MPa layer with 3.0 micron thickness Oxalic first anodization 31 MPa33 MPa 34 MPa 29 MPa layer with 10 micron thickness Type III first 25MPa 24 MPa 26 MPa 28 MPa anodization layer with 0.3 micron thicknessType III first 32 MPa 31 MPa 34 MPa 33 MPa anodization layer with 3.0micron thickness Type III first 31 MPa 29 MPa 35 MPa 34 MPa anodizationlayer with 10 micron thickness

Table 2 shows another example of electroplated aluminum coating adhesiontest results according to an embodiment, where the procedures used weresimilar to those described above for Table 1, to demonstrate therepeatability of the test results.

TABLE 2 Coating Adhesion Test Results Type III Type III Oxalic secondOxalic second second second anodization anodization anodizationanodization layer with 10 layer with 30 layer with 10 layer with 30micron micron micron micron Table 2 thickness thickness thicknessthickness Oxalic first anodization 33 MPa 35 MPa 35 MPa 35 MPa layerwith 0.3 micron thickness Oxalic first anodization 36 MPa 36 MPa 35 MPa35 MPa layer with 3.0 micron thickness Oxalic first anodization 34 MPa33 MPa 34 MPa 35 MPa layer with 10 micron thickness Type III first 22MPa 30 MPa 25 MPa 27 MPa anodization layer with 0.3 micron thicknessType III first 36 MPa 34 MPa 25 MPa 35 MPa anodization layer with 3.0micron thickness Type III first 34 MPa 32 MPa 35 MPa 35 MPa anodizationlayer with 10 micron thickness

Table 3 shows another example of electroplated aluminum coating adhesiontest results according to an embodiment, where the procedures used weresimilar to those described above for Table 1, except that the testcoupons were subjected to a vacuum bake test at about 130 degrees C. forabout 20 hours to simulate actual chamber conditions. The results ofTable 3 indicate that adhesion was maintained post-vacuum bake, whichcould indicate suitability for use with a semiconductor manufacturingchamber.

TABLE 3 Coating Adhesion Test Results Type III Type III Oxalic secondOxalic second second second anodization anodization anodizationanodization layer with 10 layer with 30 layer with 10 layer with 30micron micron micron micron Table 3 thickness thickness thicknessthickness Oxalic first anodization 33 MPa 35 MPa 35 MPa 35 MPa layerwith 0.3 micron thickness Oxalic Base first 36 MPa 33 MPa 36 MPa 35 MPaanodization layer with 3.0 micron thickness Oxalic first anodization 36MPa 35 MPa 36 MPa 34 MPa layer with 10 micron thickness Type III first23 MPa 23 MPa 22 MPa 24 MPa anodization layer with 0.3 micron thicknessType III first 36 MPa 33 MPa 34 MPa 24 MPa anodization layer with 3.0micron thickness Type III first 36 MPa 33 MPa 34 MPa 33 MPa anodizationlayer with 10 micron thickness

Table 4 shows test results of a visual inspection of samples processedaccording to the procedures described with respect to Table 1, where“good” indicates uniformity of color, “ok” indicates some non-uniformityof color, and “bad” indicates non-uniformity of color. Uniformity ofcolor can indicate uniformity in anodization finish.

TABLE 4 Coating Adhesion Test Results Type III Type III Oxalic secondOxalic second second second anodization anodization anodizationanodization layer with 10 layer with 30 layer with 10 layer with 30micron micron micron micron Table 4 thickness thickness thicknessthickness Oxalic first anodization good good ok ok layer with 0.3 micronthickness Oxalic Base first good good bad bad anodization layer with 3.0micron thickness Oxalic first anodization bad bad bad bad layer with 10micron thickness Type III first good good good good anodization layerwith 0.3 micron thickness Type III first good good bad bad anodizationlayer with 3.0 micron thickness Type III first bad bad bad badanodization layer with 10 micron thickness

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent disclosure. It will be apparent to one skilled in the art,however, that at least some embodiments of the present disclosure may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present disclosure. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentdisclosure.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.”

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the disclosure should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A chamber component for a processing chamber,comprising: a metallic article that comprises impurities; a firstanodization layer on the metallic article, the first anodization layerhaving a thickness greater than about 100 nm, wherein the firstanodization layer comprises: a dense barrier layer portion; and a porouscolumnar layer portion over the dense barrier layer portion, wherein theporous columnar layer portion comprises a plurality of pores that arefree from moisture; and an aluminum coating on the first anodizationlayer, the aluminum coating being substantially free from impurities. 2.The chamber component of claim 1, wherein the aluminum coating has athickness in a range from about 20 microns to about 80 microns.
 3. Thechamber component of claim 1 further comprising a second anodizationlayer on the aluminum coating.
 4. The chamber component of claim 3,wherein the second anodization layer has a thickness in a range fromabout 5 microns to about 30 microns.
 5. The chamber component of claim3, wherein an adhesion strength of the aluminum coating is 23-37 MPa. 6.The chamber component of claim 3, further comprising a ceramic layer onthe second anodization layer.
 7. The chamber component of claim 6,wherein the ceramic layer has a thickness in a range from about 100microns to about 300 microns.
 8. The chamber component of claim 6,wherein the ceramic layer has a thickness of about 2-10 microns.
 9. Thechamber component of claim 6, wherein the ceramic layer consistsessentially of at least one of Y₂O₃, Al₂O₃, ZrO₂, or a combinationthereof.
 10. The chamber component of claim 6, wherein the ceramic layerconsists essentially of a plasma sprayed yttrium containing oxide. 11.The chamber component of claim 6, wherein an adhesion strength of theceramic coating is about 14-25 MPa.
 12. The chamber component of claim1, wherein the chamber component is selected from a group consisting ofa showerhead, a cathode sleeve, a sleeve liner door, a cathode base, achamber liner, and an electrostatic chuck base.
 13. The chambercomponent of claim 1, wherein the first anodization layer has an aspectratio of an anodization column height to a pore diameter in a range fromabout 10 to 1 to about 2000 to
 1. 14. The chamber component of claim 13,wherein the pore diameter of the first anodization layer is about 10-50nm.
 15. The chamber component of claim 1, wherein portions of thealuminum coating are infiltrated into the plurality of pores in thefirst anodization layer.
 16. The chamber component of claim 1, whereinthe aluminum coating is an electroplated coating.
 17. The chambercomponent of claim 1, wherein the article comprises an aluminum alloy.18. The chamber component of claim 17, wherein the aluminum alloy is Al6061.
 19. The chamber component of claim 1, wherein the aluminum coatinghas a surface roughness of about 20-300 micro-inches.